More than 70 years ago, Prof. Huang Kun proposed the famous “Huang's equations” and the concept of “phonon polariton”, marking the beginning of polariton research. So far, the Huang Kun equation, named after a local Chinese scientist, remains one of the best theories for describing polaritons. In the following decades, with the rapid development of ultrafast optics, nanooptics, and terahertz physics and technology, phonon polaritons have once again become a hot research frontier. The related research on surface phonon polaritons has brought new dimensions to the localization and control of electromagnetic waves. In recent years, the team at Nankai University has developed the Huang's equations and proposed the concept of “stimulated phonon polaritons”, gradually opening the door to the study of light matter interactions in which phonon polaritons participate and lead. Various terahertz applications integrated on lithium niobate chips based on stimulated phonon polaritons have also benefited from this and achieved significant development. This article will review the relevant concepts of phonon polaritons and stimulated phonon polaritons, introduce the interaction system between light and matter under the participation of stimulated phonon polaritons, and take research on terahertz nonlinear optics and lithium niobate chip integration as examples to explain the recent development of phonon polaritons and terahertz physics.